Speed-indicating apparatus



Patented Nov. 29, 1927.

unirte STATES tenen GEORGES M QMBUR, OF VERSAILLES, FRANCE.

SPEED-INDICATING APPARATUS.

Application yfiled October 27, 1227,;Seri1a1 No. 229,250, and in France March 27, 192.6.

Alily invention relatesvto a speedindicating apparatus operated by .the velectric current from a battery designed more particularly to be applied l.to motor vehicles.

It has for its object the provision of such an `apparatus in which va measuring Vsystem `balanced by kthe action ot aspiral spring.I is acted Upon by electric impulses Vlniving a constant value and a frequency Wl'iichis proportional to `the speed ot the moving body, `followed by Abackward movements produced Vby tlie spiral spring, the positive impulses being prodncedby a frictional action upon the `Wheel of said'measuring system.

In the present apparatus'tlie positive impulses are'prodnced'by a magneticdevice in combination with anelectromagnet of which tlio circuit is closed at a frequency that is proportional Vto the, speed ot' tlie moving body.

The appended drawing sllQWs by ivay ot example a inode ofiefkiecntion pf the mechanism` of a speed indicator iacoordingy to ,the present invention. l Fig. lfis a frontdiagrainmatic.elevation ,of said mechanism.

Figx is a detail showing asection. through tlieuarmature and polar element.

Fig. 3 isa diagrammatic view ot .a modified form Qt the invention.

In the form ot tbe invention shown .in Fig. l, the measnring Wheel or elementi is balanced by the spi-ral spring 2 .vliicn tends to retain itin tlie position corresponding to tlielzerogspeed 4and suoli wheeler element is made of a magnetic'metal, sncli 'as 4very soltjironi'or instance. The spring 2 isccnnectedonone partto tbe wheel l yand on the other part tothe axle S which is connected to tlie index (not shown) in a `known mannen The wheel l is included in the y,magnetic circuit ot an electromagnet 2O of ,which one lo'litliepoles201is opposite said rWheel. ln armature 2l vmay@novein front oit the otherpole 29g/et the electromagnet. lt is ar icnlatedatZQandVdrawn back by ,a spring 23 in contact With anabutment 24 and. it carries a polar element 25` 'drawn along by the eccentij'iclug or proiection, Awhich can be made to engage tlie measuring wlieel Il or abut against `an Aalnitment Q7. Tlie magnetic` circnitot' the electromagnet is completed as .shown by tliedasli and d otul'ine Aas Will be seen invFig. Vl.

fllie diagram Vshown i'n the sectional View Fig. 2 shows tbatthe partsQ and 2l are superimposed and :thus present a large snri'aceyto the magnetic flux `passing along line A. It ywill therefore be evident ythat vat .the moment ofinagnet-ization a strong adhering pressure will be creat-ed between these parts.

Tlie electromagnet is fed by tlie current `from a battery ot accmnulators `28 ,inter- .rupted yand closed ivitlin great treqnencyby means ofabreaking vdevice 29 rotatingata speed which is a Yfunction oi' that oit tbe moving i body.

,The operation of the device is asgfolloivs:

When the current lHows through 4the electromagnet the polar element engages first .the .measuring Wlieel or ,element l tlins establishing tlie `mechanical connection and l at ythe same time :pressure `,dne to magnetizm tion is iliade to act `between (the element 25 andthe4aijnnit ure 271 yvliiclrbeing setin m0- tion and rotating at 22 gets nearertothe pole 2Q`2nn'd I presses more strongly theelement .I against the vqlieel l. Qn ftlie other liandbelng or projection 2G, which is made integral-with the armature 2l, being moved, draws alongtbe polar A'ele-ment 25%` and consegnently the measuring yvlieel a distance which is proportionatetotlie movement of the armature betiveenlfltlie abutments 24 and 27.

This arrangement liastll-egrgeat,advantage -Qf @reducing ...Simultaneously an advance movement and a progressive `braking legtfect on the arinatnrekvlas magnetic lcircuit is ,more completely closed or shortened. `friction. or clutching. eject. betweenftlie aoverlapping porti ons. otf the armature, 'V21 andthe polar element Qaduleltotlieir mntnal attraction increases With tlieprogressive shortening of tliclnagnetic ciicnit because yfotltlie increaseinmagneticflnfcdne;tosncli shortening o' the circuit. Since the polar element duringtliis .cycle of operation.isfincl'ntact with the wheel l and cannotEtlieretoremrotate clonnterclockyvisd it follows that thel counter-clockwise rotation of ytlie .armature which is magnetically clutchedmtliereto ywill also be resisted. .Oscillationso'f ytliearmature ,atftlie 4end ot its movement towards the pole piece 202 aretlnislavoided because of the ydampingaction ,dueto the increasing triction'al ,resistance `On the Iother hand tlyie aijmatnr-eattlie beginning .of its sivingltowardtlie pole piece l2.02 vis practicallyftree. .Vliiletlie elifectnpon tlielarmature depends on tli-e value, of the cinrentI the movement. or stroke of tbe armature is always the same.

Cil

When the How of the current is interrupted, the armature 2l is drawn back by the action of spring 23 and the magnetization being also interrupted, the pressure on the .measuring wheel l is relieved. A slight remanence is still apparent between the ele ment 25 and the armature, so that the re turn movement of the latter assists in disengaging the polar element 25 from the wheel l and consequently immediately frees the latter. The lug or projection 26 draws back the polar element 25 to the starting posion where it will remain on the abutment 27 untilfthe current is closed again.

On these Operations being repeated a scries of positive displacements and of disengagements of the measuring wheel take place which give the indication of the speed ac cording to the manner already known in apparatus of this kind.

In order to accelerate the demagnetization there will be advantageously provided a secondary Winding 30 shunted and mounted on the electromagnet core and having a small coeficient of self induction but resistance which is preferably higher than that of the primary winding. Atthe breaking of the circuit the breaking current flows in the reverse direction in the winding 30 and creates a demagnetizing current.

When integrating apparatus for the dis tance covered are coupled with the indicating apparatus the forward movement of these apparatus may be obtained exactly in the manner above described for the forward displacement of the measuring wheel.

Fig. 3 of the annexed drawings is a diagram of this arrangement.

Upon a spindle preferably in line with that of the measuring wheel but not connected with it is keyed a second wheel 3l of magnetic metal which constitutes the first wheel of the integrating mechanism. A second polar mass element 251 is placed on the other face of the armature 2l rotating on the spindle 22. The polar elements 25 and 251 are traversed and operated by an eccentric lug or projection 26.

It will. be evident that in operation two magnetic circuits will be established as indicated at A B and A B1 and that the operations above described will new take place on both wheels.

Consequently a feeding motion of the measuring wheel and of the driving wheel of the integrating device will take place.

Having now described my invention I declare that what I claim and desire to secure by Letters Patent of the United States is:

1. A motor for speed indicating apparatus comprising a rotatable element, an electro-magnet, one pole of the electro-magnet being disposed adjacent said rotatable element, an armature adapted to be attracted by the second pole of said electro-magnet when the same is energized, a spring for re sto 'ing the armature to its initial position when the electro-magnet is de-energized, and a magnetizable pawl oscillated by said armature and adapted to advance and then release said rotatable element, the pawl coA operating with the armature and the rotatable element to complete a magnetic circuit for the flux of said electro-magnet- 2. rlChe motor according to claim l further characterized in that said armature is pivoted to swing toward the said second pole of the electro-magnet when the latter is energized, and abutments to limit the swing of said armature in either direction.

The motor according to claim l furtluir characterized in that the said armature is pivotally mounted, the said pawl beingpivoted to said armature eccentrically with respect to the pivotal axis thereof.

4t. The motor according to claim l further characterized in that the said armature is pivotally mounted, the said pawl being pivotcd to said armature eccentrically with respect to the pivotal axis thereof, the said armature and pawl also being` held in fric tional contact by their mutual attraction when magnetized, whereby angular movc ments of thc armature are transmitted to the pawl.

5. A motor for speed indicating apparatus comprising a rotatable wheel, an electromagnet, one pole of the electro-magnet being disposed adjacent said wheel, and magnetizable driving means actuated by said electro-magnet and adapted to advance the said wheel, said driving means being interv posed between the second pole of the electromagnet and the said wheel whereby a mag netic circuit is provided, said circuit including the said magnetizable driving means, the wheel, and the electro-magnet.

6. A motor for speed indicating apparatus comprising' a rotatable wheel, an electromagnet, one pole of said elect1'omagnet tranmitting flux directly to said wheel, a

pivoted armature near the other pole of said i clectroemagnet, an abutment liniitiing the movement ot said arnniture, a return spring tending in opposition to the attraction of said electro-magnet to move said arn'iature towards said abutment, a pawl actuated by the movement of said armature, said pawl being magnetically drawn into contact with the wheel by flux which passes through the armature and the wheel when the electromagnet is energized.

7. The motor according to claim (i further characterized in that. a second abutment is provided to limit the rmiwcmcnt of said pawl away from the wheel.

8. A motor for speed indicating apparatus comprising a wheel, an electro-magnet, a pivoted armature drawn toward a pole of said electro-magnet when the same is enertion set up by the magnetization o1? .unifi electro-magnet whereby through said frietional engagement the angular movements of the armature will be transn'iitted to the pawl.

In Witness whereof`V signed my name'.

GEORGES MOMBUR.

I have hereunto 

